Tobacco treatment



Patented May 11, 1937 UNITED STATES TOBACCO TREATMENT Paul La Frone Magill, Ransoinville, N. Y., as-

signor to E. I. du Pont de Nemours & Company,

Wilmington, Del., a

corporation of Delaware No Drawing. Application April 15, 1936, Serial No. 74,599

'1 Claims.

This invention relates to the treatment of tobacco and more particularly to a method for preserving cured tobacco and inhibiting its drying out.

To maintain the desired smoking quality of tobacco it is necessary that a certain moisture content of tobacco be maintained. Also, in the manufacture of cigars and in other tobacco processing operations, it is necessary to maintain 10 the tobacco in a moist condition in order that the leaves will have the proper flexibility. It has been common practice heretofore to treat tobacco with glycerin, adding a small amount within the range of 1 to 10%, e. g., around 5% 5 by weight of tobacco. The hygroscopic properties of glycerin inhibits drying out to some extent.

The storage of humidified tobacco under some 20 conditions results in an attack by molds or other fungi. Tobacco which has been-treated with glycerin is quite susceptible to such fungus at-- tack.

An object of the present invention is to provide an improved method of treating tobacco whereby drying out is inhibited and at the same time the tobacco is preserved against fungus attack and other spoilage. Other objects will be hereinafter apparent.

I have discovered that by applying to tobacco a small amount of formamide, the tobacco may be preserved from the attack of fungus and like pests and at the same time the hygroscopic nature of the formamide inhibits drying out of 35 the tobacco. I have further found that the inhibition of drying out by the use of formamide is greater than that'obtained by using gylcerin for the same purpose.

In practicing my invention I apply from i to usually around 5%, by weight of formamide to the tobacco by any suitable means. The formamide may be applied at any desired stage in the processing of the tobacco; for example it may be applied to the leaves directly after they 45 have been cured or during some stage of the curing process or it may be applied after the leaves have been cut. Formamide may be applied as such or in the form of an aqueous solution. During the processing of tobacco it is common prac- 50 tice to humidity the leaves by spraying with water at certain stages of the process. In the application oi my invention to such curing process, I prefer to spray the tobacco with water in which a all amount of iormamide has been dissolved.

Fcrmamide in the pure state is a colorless mobile liquid boiling at around 200 (3., having good chemical stability at temperatures below its boiling point, and very soluble in water. It does not impart any undesirable odor, taste or other undesirable properties to tobacco treated with it;'

nor does it have any adverse eflect on the smoking quality of the tobacco.

The following example illustrates the superior eifect of formamide in inhibiting the drying out 5 of tobacco.

1 Example Chopped up cured tobacco was divided into three portions, one of which was sprayed with an aqueous solution of glycerin, another sprayed with an aqueous solution of formamide and the third left untreated. The treated portions contained about 5% by weight of the glycerin or Percentage of moisture lost on standing 18 hours Percent Untreated tobacco 26.7 Glycerin treated tobacco 26. 6 Formamide treated tobacco 25.6

The two samples of tobacco treated with formamide and glycerin were placed in two separate beakers loosely covered with a watch glass and set aside in the dark for two months. At the end of this time the sample which had been treated with glycerin was heavily encrusted throughout with a mass of white fungus. The

sample treated with formamide did not show any evidence of fungus and appeared in every way identical with the untreated tobacco.

I claim:

1. A process for treating tobacco which comprises applying formamide thereto.

2. A process for treating tobacco which comprises applyingan aqueous solution offormamide thereto.

3. A process for treating tobacco which comprises applying formamide thereto in an amount equal to 1 to 10% by weightof the tobacco.

4. A process for treating tobacco which comprises applying formamide thereto in an amount equal to about 5% by weight or the tobacco.

5. A composition of matter comprising tobacco and formal-hide.

6. A composition of matter comprising tobacco and 1 to 10% by weight of formamide';

7. A composition of matter comprising to bacco and about 5% by weight of formrzmide.

PAUL LA FRONE MAGEL. 

